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    <title>html5 programming</title>
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    <h1>H1:html5</h1>
    <h2>H2:html5</h2>
    <h3>H3:html5</h3>
    <h4>H4:html5</h4>
    <h5>H5:html5</h5>
    <h6>H6:html5</h6>

    <p>html5,i love it.</p><p>me too.</p>
    <p>very good</p>

    <details>
        i love html5 programming.
        <p>
            hi
        </p>
    </details>

    <details>
        <summary>
            html
        </summary>
        i love html5 programming.
    </details>

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